This invention relates to a device for projecting a defined light beam onto a photosensitive area, particularly for testing the performance of a photovoltaic module.
Performance tests of this kind require a well defined light beam as far as global intensity, local intensity distribution and spectral composition are concerned. For DC photovoltaic modules, pulsed simulated light sources are preferred over natural sunlight due to their well-known and constant light spectrum, their stable intensity over the measuring cycle (about 2 ms), their availability over the entire year and the low and constant temperature level to which the module is subjected during the short term test.
However, some new technology modules such as multi-junction solar panels or AC photovoltaic modules require measuring cycles of longer duration for which high intensity artificial light sources are only available at high costs.